Direct conversion of aromatic amides into crystalline covalent triazine frameworks by a condensation mechanism

Multiple studies have recently been conducted to develop well-ordered covalent triazine-based frameworks (CTFs). To date, few studies have demonstrated CTFs with high crystallinity using novel synthesis strategies and different building blocks. To construct highly crystalline CTFs with enhanced performance, significant technical advancements in fundamental chemical insights are essential. Here, we report that the phosphorus pentoxide (P2O5)-catalyzed condensation of biphenyl-based amide and nitrile monomers can produce ordered pCTF-2. The pCTF-2A directly synthesized from amide monomers showed unusually higher crystallinity and porosity than the pCTF-2N synthesized from nitrile monomers. Based on experimental results, density functional theory (DFT) calculations revealed that amide groups can be directly trimerized into triazine rings in the presence of P2O5, which is a more thermodynamically favorable reaction than those from nitrile groups. Based on this mechanistic insight, the efficient and better synthesis strategy provides an effective pathway for the formation of crystalline CTFs

Enhanced electrocatalytic performance of Pt nanoparticles on triazine-functionalized graphene nanoplatelets for both oxygen and iodine reduction reactions

Platinum (Pt) nanoparticles were stably anchored on triazine-functionalized graphene nanoplatelets (TfGnPs), which were prepared by a two-step reaction starting from carboxylic acid-(CGnPs), acyl chloride-(AcGnPs) and amide-functionalized graphene nanoplatelets (AfGnPs). The resulting Pt nanoparticles on TfGnPs (Pt/TfGnPs) exhibited outstanding electrocatalytic activity with significantly enhanced stability compared with commercial Pt-based catalysts for the oxygen reduction reaction (ORR) in fuel cells (FCs) and the iodine reduction reaction (IRR) in dye-sensitized solar cells (DSSCs). For the ORR in FCs, the onset and half-wave potentials of Pt/TfGnPs under acidic conditions displayed greater positive shifts to 0.58 and 0.53 V, respectively, than those of the commercial Pt/C catalyst (0.57 and 0.52 V). For the IRR in DSSCs, Pt/TfGnPs displayed a reduced charge transfer resistance (R-ct) of 0.13 Omega cm(2) at the CE/electrolyte interface. This value was much lower than the Pt CE of 0.52 Omega cm(2). More importantly, Pt/TfGnPs exhibited profoundly improved electrochemical stability in both the ORR and IRR compared to the Pt-based catalysts. The combination of extraordinarily high electrocatalytic activity with stability could be attributed to the high specific surface area (963.0 m(2) g(-1)) and the triazine units of the TfGnPs, respectively, which provided more active sites and stably anchored the Pt nanoparticles

PMK-S005 Alleviates Age-Related Gastric Acid Secretion, Inflammation, and Oxidative Status in the Rat Stomach

BACKGROUND/AIMS: The aim of this study was to evaluate the effect of the synthetic S-allyl-l-cysteine (SAC) PMK-S005 on gastric acid secretion, inflammation, and antioxidant enzymes in aging rats. METHODS: The rats were divided into four groups at 31 weeks of age and were continuously fed a diet containing a vehicle control, PMK-S005 (5 or 10 mg/kg), or lansoprazole (5 mg/kg). Gastric acid secretion and connective tissue thickness of the lamina propria were evaluated at 74 weeks and 2 years of age. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and COX-2 levels were measured by using enzyme-linked immunosorbent assays (ELISAs) or Western blot assays. Levels of antioxidant enzymes, including heme oxyganase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), were also measured. RESULTS: As the rats aged, gastric acid secretion significantly decreased, and the connective tissue of the lamina propria increased. However, 74-week-old rats in the PMK-S005 group exhibited greater levels of gastric acid secretion than those of the control and lansoprazole groups. The increase of TNF-α, IL-1β, and COX-2 expression in 74-week and 2-year-old control rats were inhibited by PMK-S005. In addition, the decrease in HO-1 and NQO-1 protein expression that occurred with aging was inhibited by PMK-S005 in the 74-week-old rats. CONCLUSIONS: These results suggest that PMK-S005 has therapeutic potential as an antiaging agent to ameliorate age-related gastric acid secretion, inflammation, and oxidative stress in the stomach